The DC motor speed controller can not only control the speed, but also the direction of a DC motor using a PMW DC voltage. Features: High performance. No noise, high power and high efficiency. With forward reverse switch. Adjust the speed and direction easily. Control and adjust the speed of a DC motor with this controller. Light weight, heavy current, wide voltage. High reliability. High torque, low heat generation. Specification: Working Voltage: DC 12V-40V Maximum Output Power: 120W Maximum Continuous Output Current: 3A PWM Frequency: 15kHz Duty Cycle Adjustable: 0- The Operation Environment Temperature: -20C-40C Material: Aluminium Alloy Item size: 9 * 3.8 * 3cm / 3.54 * 1.5 * 1.18in(L * W * H) Item weight: Approx. 69g / 2.43oz Package size: 14.6 * 10.3 * 3.5cm / 5.75 * 4.06 * 1.38in(L * W * H) Package weight: 71g / 2.5oz Package List: 1 * DC Motor Speed Controller Note: It can NOT be used to the BRUSHLESS motor.